1 /* 2 * QEMU seccomp test suite 3 * 4 * Copyright (c) 2021 Red Hat, Inc. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21 #include "qemu/osdep.h" 22 #include "qemu/config-file.h" 23 #include "qemu/option.h" 24 #include "sysemu/seccomp.h" 25 #include "qapi/error.h" 26 #include "qemu/module.h" 27 28 #include <sys/syscall.h> 29 30 static void test_seccomp_helper(const char *args, bool killed, 31 int errnum, int (*doit)(void)) 32 { 33 if (g_test_subprocess()) { 34 QemuOptsList *olist; 35 QemuOpts *opts; 36 int ret; 37 38 module_call_init(MODULE_INIT_OPTS); 39 olist = qemu_find_opts("sandbox"); 40 g_assert(olist != NULL); 41 42 opts = qemu_opts_parse_noisily(olist, args, true); 43 g_assert(opts != NULL); 44 45 parse_sandbox(NULL, opts, &error_abort); 46 47 /* Running in a child process */ 48 ret = doit(); 49 50 if (errnum != 0) { 51 g_assert(ret != 0); 52 g_assert(errno == errnum); 53 } else { 54 g_assert(ret == 0); 55 } 56 57 _exit(0); 58 } else { 59 /* Running in main test process, spawning the child */ 60 g_test_trap_subprocess(NULL, 0, 0); 61 if (killed) { 62 g_test_trap_assert_failed(); 63 } else { 64 g_test_trap_assert_passed(); 65 } 66 } 67 } 68 69 70 static void test_seccomp_killed(const char *args, int (*doit)(void)) 71 { 72 test_seccomp_helper(args, true, 0, doit); 73 } 74 75 static void test_seccomp_errno(const char *args, int errnum, int (*doit)(void)) 76 { 77 test_seccomp_helper(args, false, errnum, doit); 78 } 79 80 static void test_seccomp_passed(const char *args, int (*doit)(void)) 81 { 82 test_seccomp_helper(args, false, 0, doit); 83 } 84 85 #ifdef SYS_fork 86 static int doit_sys_fork(void) 87 { 88 int ret = syscall(SYS_fork); 89 if (ret < 0) { 90 return ret; 91 } 92 if (ret == 0) { 93 _exit(0); 94 } 95 return 0; 96 } 97 98 static void test_seccomp_sys_fork_on_nospawn(void) 99 { 100 test_seccomp_killed("on,spawn=deny", doit_sys_fork); 101 } 102 103 static void test_seccomp_sys_fork_on(void) 104 { 105 test_seccomp_passed("on", doit_sys_fork); 106 } 107 108 static void test_seccomp_sys_fork_off(void) 109 { 110 test_seccomp_passed("off", doit_sys_fork); 111 } 112 #endif 113 114 static int doit_fork(void) 115 { 116 int ret = fork(); 117 if (ret < 0) { 118 return ret; 119 } 120 if (ret == 0) { 121 _exit(0); 122 } 123 return 0; 124 } 125 126 static void test_seccomp_fork_on_nospawn(void) 127 { 128 test_seccomp_killed("on,spawn=deny", doit_fork); 129 } 130 131 static void test_seccomp_fork_on(void) 132 { 133 test_seccomp_passed("on", doit_fork); 134 } 135 136 static void test_seccomp_fork_off(void) 137 { 138 test_seccomp_passed("off", doit_fork); 139 } 140 141 static void *noop(void *arg) 142 { 143 return arg; 144 } 145 146 static int doit_thread(void) 147 { 148 pthread_t th; 149 int ret = pthread_create(&th, NULL, noop, NULL); 150 if (ret != 0) { 151 errno = ret; 152 return -1; 153 } else { 154 pthread_join(th, NULL); 155 return 0; 156 } 157 } 158 159 static void test_seccomp_thread_on(void) 160 { 161 test_seccomp_passed("on", doit_thread); 162 } 163 164 static void test_seccomp_thread_on_nospawn(void) 165 { 166 test_seccomp_passed("on,spawn=deny", doit_thread); 167 } 168 169 static void test_seccomp_thread_off(void) 170 { 171 test_seccomp_passed("off", doit_thread); 172 } 173 174 static int doit_sched(void) 175 { 176 struct sched_param param = { .sched_priority = 0 }; 177 return sched_setscheduler(getpid(), SCHED_OTHER, ¶m); 178 } 179 180 static void test_seccomp_sched_on_nores(void) 181 { 182 test_seccomp_errno("on,resourcecontrol=deny", EPERM, doit_sched); 183 } 184 185 static void test_seccomp_sched_on(void) 186 { 187 test_seccomp_passed("on", doit_sched); 188 } 189 190 static void test_seccomp_sched_off(void) 191 { 192 test_seccomp_passed("off", doit_sched); 193 } 194 195 static bool can_play_with_seccomp(void) 196 { 197 g_autofree char *status = NULL; 198 g_auto(GStrv) lines = NULL; 199 size_t i; 200 201 if (!g_file_get_contents("/proc/self/status", &status, NULL, NULL)) { 202 return false; 203 } 204 205 lines = g_strsplit(status, "\n", 0); 206 207 for (i = 0; lines[i] != NULL; i++) { 208 if (g_str_has_prefix(lines[i], "Seccomp:")) { 209 /* 210 * "Seccomp: 1" or "Seccomp: 2" indicate we're already 211 * confined, probably as we're inside a container. In 212 * this case our tests might get unexpected results, 213 * so we can't run reliably 214 */ 215 if (!strchr(lines[i], '0')) { 216 return false; 217 } 218 219 return true; 220 } 221 } 222 223 /* Doesn't look like seccomp is enabled in the kernel */ 224 return false; 225 } 226 227 int main(int argc, char **argv) 228 { 229 g_test_init(&argc, &argv, NULL); 230 if (can_play_with_seccomp()) { 231 #ifdef SYS_fork 232 g_test_add_func("/softmmu/seccomp/sys-fork/on", 233 test_seccomp_sys_fork_on); 234 g_test_add_func("/softmmu/seccomp/sys-fork/on-nospawn", 235 test_seccomp_sys_fork_on_nospawn); 236 g_test_add_func("/softmmu/seccomp/sys-fork/off", 237 test_seccomp_sys_fork_off); 238 #endif 239 240 g_test_add_func("/softmmu/seccomp/fork/on", 241 test_seccomp_fork_on); 242 g_test_add_func("/softmmu/seccomp/fork/on-nospawn", 243 test_seccomp_fork_on_nospawn); 244 g_test_add_func("/softmmu/seccomp/fork/off", 245 test_seccomp_fork_off); 246 247 g_test_add_func("/softmmu/seccomp/thread/on", 248 test_seccomp_thread_on); 249 g_test_add_func("/softmmu/seccomp/thread/on-nospawn", 250 test_seccomp_thread_on_nospawn); 251 g_test_add_func("/softmmu/seccomp/thread/off", 252 test_seccomp_thread_off); 253 254 if (doit_sched() == 0) { 255 /* 256 * musl doesn't impl sched_setscheduler, hence 257 * we check above if it works first 258 */ 259 g_test_add_func("/softmmu/seccomp/sched/on", 260 test_seccomp_sched_on); 261 g_test_add_func("/softmmu/seccomp/sched/on-nores", 262 test_seccomp_sched_on_nores); 263 g_test_add_func("/softmmu/seccomp/sched/off", 264 test_seccomp_sched_off); 265 } 266 } 267 return g_test_run(); 268 } 269